fix(remove, prune, merge): target the named worktree, retain shared branches

docs/content/faq.md

@@ -191,6 +191,8 @@ For the full algorithm, see [Branch cleanup](@/remove.md#branch-cleanup) — it
 
 Use `-D` to force-delete branches with unmerged changes. Use `--no-delete-branch` to keep the branch regardless of status.
 
+A branch checked out in a second worktree is retained regardless, `-D` included. Deleting it would leave that worktree unable to resolve `HEAD`; only `git worktree add --force` produces that state.
+
 ### Other cleanup
 
 - `wt remove` — besides the target worktree, two cleanup mechanisms run. The removed worktree's own `git fsmonitor--daemon` (git's per-worktree filesystem watcher under `core.fsmonitor=true`, which would leak once its worktree is gone) is sent `git fsmonitor--daemon stop`, then force-terminated (`SIGTERM`, then `SIGKILL`) via the PID resolved from its IPC socket if it didn't exit. A background sweep then deletes `.git/wt/trash/` entries older than 24 hours (directories orphaned when a previous background removal was interrupted) and terminates fsmonitor daemons whose worktree no longer exists (orphans from `git worktree remove`, `rm -rf`, or a crashed `wt`)

docs/content/remove.md

@@ -54,6 +54,8 @@ The 'same commit' check uses the local default branch; for other checks, 'target
 
 Branches matching these conditions and with empty working trees are dimmed in `wt list` as safe to delete.
 
+Those six ask whether deleting loses work. A branch checked out in a second worktree (only reachable via `git worktree add --force`) fails a different test: deleting the ref would leave that worktree unable to resolve `HEAD`, which is why `git branch -d` refuses the same delete. Such a branch is retained whatever `-D` asks, and the surviving checkout is named.
+
 ## Force flags
 
 Worktrunk has two force flags for different situations:

plugins/worktrunk/skills/worktrunk/reference/faq.md

@@ -186,6 +186,8 @@ For the full algorithm, see [Branch cleanup](https://worktrunk.dev/remove/#branc
 
 Use `-D` to force-delete branches with unmerged changes. Use `--no-delete-branch` to keep the branch regardless of status.
 
+A branch checked out in a second worktree is retained regardless, `-D` included. Deleting it would leave that worktree unable to resolve `HEAD`; only `git worktree add --force` produces that state.
+
 ### Other cleanup
 
 - `wt remove` — besides the target worktree, two cleanup mechanisms run. The removed worktree's own `git fsmonitor--daemon` (git's per-worktree filesystem watcher under `core.fsmonitor=true`, which would leak once its worktree is gone) is sent `git fsmonitor--daemon stop`, then force-terminated (`SIGTERM`, then `SIGKILL`) via the PID resolved from its IPC socket if it didn't exit. A background sweep then deletes `.git/wt/trash/` entries older than 24 hours (directories orphaned when a previous background removal was interrupted) and terminates fsmonitor daemons whose worktree no longer exists (orphans from `git worktree remove`, `rm -rf`, or a crashed `wt`)

plugins/worktrunk/skills/worktrunk/reference/remove.md

@@ -53,6 +53,8 @@ The 'same commit' check uses the local default branch; for other checks, 'target
 
 Branches matching these conditions and with empty working trees are dimmed in `wt list` as safe to delete.
 
+Those six ask whether deleting loses work. A branch checked out in a second worktree (only reachable via `git worktree add --force`) fails a different test: deleting the ref would leave that worktree unable to resolve `HEAD`, which is why `git branch -d` refuses the same delete. Such a branch is retained whatever `-D` asks, and the surviving checkout is named.
+
 ## Force flags
 
 Worktrunk has two force flags for different situations:

src/cli/mod.rs

@@ -1277,6 +1277,8 @@ The 'same commit' check uses the local default branch; for other checks, 'target
 
 Branches matching these conditions and with empty working trees are dimmed in `wt list` as safe to delete.
 
+Those six ask whether deleting loses work. A branch checked out in a second worktree (only reachable via `git worktree add --force`) fails a different test: deleting the ref would leave that worktree unable to resolve `HEAD`, which is why `git branch -d` refuses the same delete. Such a branch is retained whatever `-D` asks, and the surviving checkout is named.
+
 ## Force flags
 
 Worktrunk has two force flags for different situations:

src/commands/picker/mod.rs

@@ -2803,6 +2803,7 @@ pub mod tests {
             integration_reason: None,
             force_worktree: false,
             removed_commit: None,
+            branch_checked_out_at: None,
         };
 
         AltXRemover::do_removal(&repo, &result, &Approvals::default()).unwrap();
@@ -2826,6 +2827,7 @@ pub mod tests {
             pruned: false,
             target_branch: None,
             integration_reason: None,
+            branch_checked_out_at: None,
         };
         AltXRemover::do_removal(&repo, &result, &Approvals::default()).unwrap();
 
@@ -2852,6 +2854,7 @@ pub mod tests {
             pruned: false,
             target_branch: None,
             integration_reason: None,
+            branch_checked_out_at: None,
         };
         AltXRemover::do_removal(&repo, &result, &Approvals::default()).unwrap();
 
@@ -2898,6 +2901,7 @@ pub mod tests {
             integration_reason: None,
             force_worktree: false,
             removed_commit: None,
+            branch_checked_out_at: None,
         };
 
         AltXRemover::do_removal(&repo, &result, &Approvals::default()).unwrap();
@@ -2989,6 +2993,7 @@ pub mod tests {
             integration_reason: None,
             force_worktree: false,
             removed_commit: None,
+            branch_checked_out_at: None,
         };
 
         // Empty approvals → `approve_readonly` drops the unapproved project
@@ -3676,6 +3681,7 @@ pub mod tests {
             integration_reason: None,
             force_worktree: false,
             removed_commit: None,
+            branch_checked_out_at: None,
         };
         assert_eq!(
             super::removal_failure_subject(&branched),
@@ -3692,6 +3698,7 @@ pub mod tests {
             integration_reason: None,
             force_worktree: false,
             removed_commit: None,
+            branch_checked_out_at: None,
         };
         assert_eq!(
             super::removal_failure_subject(&detached),
@@ -3704,6 +3711,7 @@ pub mod tests {
             pruned: false,
             target_branch: None,
             integration_reason: None,
+            branch_checked_out_at: None,
         };
         assert_eq!(
             super::removal_failure_subject(&branch_only),
@@ -4040,6 +4048,7 @@ pub mod tests {
             integration_reason: None,
             force_worktree: false,
             removed_commit: None,
+            branch_checked_out_at: None,
         };
 
         assert_eq!(
@@ -4138,6 +4147,7 @@ pub mod tests {
             integration_reason: None,
             force_worktree: false,
             removed_commit: None,
+            branch_checked_out_at: None,
         };
         assert!(super::removal_target_still_present(
             &repo,
@@ -4155,6 +4165,7 @@ pub mod tests {
             pruned: false,
             target_branch: None,
             integration_reason: None,
+            branch_checked_out_at: None,
         };
         assert!(super::removal_target_still_present(&repo, &present_branch));
 
@@ -4164,6 +4175,7 @@ pub mod tests {
             pruned: false,
             target_branch: None,
             integration_reason: None,
+            branch_checked_out_at: None,
         };
         assert!(!super::removal_target_still_present(&repo, &gone_branch));
     }
@@ -4184,6 +4196,7 @@ pub mod tests {
                 pruned: false,
                 target_branch: None,
                 integration_reason: integration,
+                branch_checked_out_at: None,
             }
         };
 
@@ -4197,6 +4210,7 @@ pub mod tests {
             integration_reason: None,
             force_worktree: false,
             removed_commit: None,
+            branch_checked_out_at: None,
         };
         assert!(
             super::removal_will_remove_target(&worktree),
@@ -4243,6 +4257,7 @@ pub mod tests {
             integration_reason: None,
             force_worktree: false,
             removed_commit: None,
+            branch_checked_out_at: None,
         };
         assert!(
             super::removal_targets_current_worktree(&worktree(true)),
@@ -4259,6 +4274,7 @@ pub mod tests {
                 pruned: false,
                 target_branch: None,
                 integration_reason: None,
+                branch_checked_out_at: None,
             }),
             "a branch-only row has no worktree to be standing in"
         );

src/commands/remove.rs

@@ -101,7 +101,7 @@ fn validate_remove_targets(
         };
 
         match resolved {
-            ResolvedWorktree::Worktree { path, branch } => {
+            ResolvedWorktree::Worktree { path, branch: _ } => {
                 // Use canonical paths to avoid symlink/normalization mismatches
                 let path_canonical = dunce::canonicalize(&path).unwrap_or(path);
                 let is_current = current_worktree.as_ref() == Some(&path_canonical);
@@ -121,13 +121,14 @@ fn validate_remove_targets(
                     continue;
                 }
 
-                // Non-current worktree: remove by branch name, or by path for
-                // detached worktrees (which have no branch).
-                let target = if let Some(ref branch_name) = branch {
-                    RemoveTarget::Branch(branch_name)
-                } else {
-                    RemoveTarget::Path(&path_canonical)
-                };
+                // Remove exactly the resolved worktree by its path. Targeting by
+                // branch name would resolve an ambiguous branch (one checked out
+                // in several worktrees via `git worktree add --force`) back to
+                // git's first-listed worktree — removing the wrong one — whereas
+                // the path is unambiguous. `prepare_worktree_removal` still
+                // deletes the branch when it's the sole checkout, and retains it
+                // otherwise (see its shared-branch handling).
+                let target = RemoveTarget::Path(&path_canonical);
                 match repo.prepare_worktree_removal(
                     target,
                     deletion_mode,